通辽市森林生态系统植被碳贮量估算研究

以生物量与立木蓄积量为基础,对内蒙古通辽市森林生态系统植被碳贮量进行了估算。结果表明：通辽市森林生态系统植被总碳贮量为1 307.03万t,其中,按林种分,用材林、防护林、特用林、疏林、经济林、灌木林、散生木、四旁树的碳贮量分别为：439.42万t、357.35万t、11.53万t、8.94万t、11.12万t、462.70万t、0.74万t、15.23万t;按树种分,杨树碳贮量最大,为680.88万t,占乔木林碳贮量的81.7%;按旗县分,扎鲁特旗森林植被碳贮量最大,为432.56万t,占总碳贮量的32.41%。     

Chrysophyte scales in lake sediments provide evidence of recent acidification in two Quebec (Canada) lakes

Several lake surveys have indicated that many lakes in Quebec are sensitive to acidification, but no historical data are available to provide conclusive evidence of lake acidification. Paleolimnological studies can provide such evidence. Chrysophycean algal microfossils were analyzed from the sediments of Lake Bonneville and Lake Truite Rouge in Quebec. The chrysophyte flora in the study lakes was stable until 40 yr ago, but since then the taxa characteristic of acidic or slightly acidic waters increased in abundance. The study provides evidence of recent lake acidification in Quebec.     

Micronutrients (Fe,Mn, Zn and Cu) balance under long-term application of fertilizer and manure in a tropical rice-rice system

Purpose

The balance of micronutrients in soils is important in nutrient use efficiency, environmental protection and the sustainability of agro-ecological systems. The deficiency or excess of micronutrients in the plough layer may decrease crop yield and/or quality. Therefore, it is essential to maintain appropriate levels of micronutrients in soil, not only for satisfying plant needs in order to sustain agricultural production but also for preventing any potential build-up of certain nutrients.

Materials and methods

A long-term fertilizer experiment started in 1969 at Central Rice Research Institute, Cuttack, Odisha, India. Using this experiment, a study was conducted to analyze the balance of micronutrients and their interrelationship. The experiment was composed of ten nutrient management treatments viz. control; nitrogen (N); N + phosphorus (NP); N + potassium (NK); nitrogen, phosphorus and potassium (NPK); farmyard manure (FYM); N + FYM; NP + FYM; NK + FYM; and NPK + FYM with three replications. Micronutrients in soil (total and available), added fertilizers and organic manures and in rice plant were analyzed. Besides, atmospheric deposition of the micronutrients to the experimental site was also calculated. A micronutrient balance sheet was prepared by the difference between output and input of total micronutrients.

Results and discussion

Application of FYM alone or in combination with chemical fertilizer increased the diethylenetriamine pentaacetate (DTPA)-extractable Fe, Mn and Zn over the control treatment. The treatment with NPK + FYM had the highest soil DTPA-extractable Fe, Mn, Zn and Cu after 41 years of cropping and fertilization. Application of chemical fertilizers without P decreased the DTPA-extractable Zn over the control while the inclusion of P in the fertilizer treatments maintained it on a par with the control. The application of P fertilizer and FYM either alone or in combination significantly increased the contents of total Fe, Mn, Zn and Cu in soil mainly due to their micronutrient content and atmospheric depositions. A negative balance of Zn was observed in the N, NP, NK and NPK treatments, while a positive balance observed in the remaining treatments. The balance of Mn was negative in all the treatments, due to higher uptake by the rice crop than its addition.

Conclusions

Long-term application of chemical fertilizers together with FYM maintained the availability of micronutrients in soil and, thus, their uptake by rice crop.

     

Rice bran lysolecithin as a source of energy in broiler chicken diet

1. Rice bran lysolecithin (RBL) was evaluated in broiler chicken diets. In the first experiment, RBL was included in diet at 0, 0·5, 2, 8 and 32?g/kg and fed to 250 broiler chickens from 0 to 42?d of age. In the second experiment, RBL was fed at 0, 25 and 50?g/kg diet to 405?day-old broiler chickens until 21?d of age, while during the finisher phase (22–35?d of age) chickens receiving each concentration of RBL were given all three concentrations of RBL in a 3?×?3 factorial manner. The diets were isocaloric.

2. Body weight, food consumption and food conversion efficiency were unaffected by feeding RBL, while the weight of pancreas increased at ≥2?g/kg of RBL in diet (experiment 1). In experiment 2, body weight was greater in the chickens receiving RBL at either 25 or 50?g/kg (21?d) and 50?g/kg (35?d of age). At 21?d of age, food consumption was greater at 25 or 50?g RBL/kg diet, while food conversion efficiency improved with 50?g RBL/kg diet.

3. Fat digestibility increased with RBL at 32?g/kg (experiment 1) and ≤25?g/kg (experiment 2). Rice bran lysolecithin increased ready to cook weight at 50?g/kg during starter phase and decreased abdominal fat at 25 and 50?g/kg during finisher phase (experiment 2). Liver and meat fat content were not affected.

4. It is concluded that lysolecithin from rice bran oil could be used as energy supplement in broiler chicken diet.     

Biotypes and sensitivity screening Yersinia enterocolitica as an infective agent in man and swine in Nigeria.

Diarrhoeic faecal samples from 210 humans and 192 swine were screened for Yersinia enterocolitica in 1990. Ten and 8 Y. enterocolitica strains were isolated from pig and man, respectively. The isolates were found to belong to Wauter's biotypes 1, 2, 3 and 4. Biotype 2 was isolated mainly from human stool samples. Biotype 3 was found only in swine while biotypes 1 and 4 were isolated from both man and swine. All the 18 strains showed varying degrees of sensitivity to antibiotics used in this investigation. The organisms were consistent in their resistance to ampicillin and penicillin.     

Histamine in egg yolk: heat resistance and relation to production status

1. The presence of histamine in egg yolk, its losses during storage, incubation and heating, and its relationship to cage density stress and the egg production status of hens are described. 2. A significant (P less than 0.05) reduction in the histamine concentration of egg yolk was noted after incubating or heating egg yolks or on storage eggs. 3. Histamine concentration was greater in the yolks of high egg producing hens. 4. The concentrations of histamine in egg yolks did not change significantly (P less than 0.05) on keeping the hens individually in a cage, pairing them in the same size cage or after separating them again to individual cages.     

Studies on the development and survival periods of the non-parasitic stages of Boophilus microplus (Canestrini), in the climatic conditions of Ranchi (India).

Engorged female ticks of Boophilus microplus were exposed in wire-gauze cylinders and glass tubes in an experimental grass plot at monthly intervals during 1989, and egg laying, egg development and larval survival periods observed and recorded. Rainfall and atmospheric relative humidity had an important influence on tick activity. Egg production was maximum, hatching percentage was high, incubation and prehatch periods were short, and larval survival and total longevity periods were long for ticks exposed during the warm and humid rainy season from June to September. Dry atmospheric conditions severely affected egg development, egg hatch and larval survival. Eggs failed to hatch in the dry months from December to April and only 29-38% hatched after a long incubation period of 41 days in November and May. On grass, the larvae of ticks exposed in November survived for the shortest period of 28 days and the larvae of ticks exposed in June survived for the longest period of 133 days. Low winter temperatures reduced egg production and prolonged the pre-oviposition, oviposition and incubation periods. It is suggested that the results of this study might be helpful in the development of measures to control tick infestation by planned dipping and restricted grazing during the period from late June to January when the pasture has a substantial load of larval ticks.     

Antioxidant Potential and Health Relevant Functionality of Traditionally Processed <Emphasis Type="Italic">Cassia hirsuta</Emphasis> L. Seeds: An Indian Underutilized Food Legume

The methanolic extract of Cassia hirsuta L. seed materials, an underutilized food legume collected from India, was analyzed for antioxidant activity and health relevant functionality. The methanolic extract of raw seeds contained a total free phenolic content of 15.82?±?1.69 g catechin equivalent/100 g extract DM. Encouraging levels of ferric reducing/antioxidant power (FRAP, 1,446 mmol Fe[II]/mg extract), inhibition of ß-carotene degradation (48.81%) and scavenging activity against DPPH (64.40%) and superoxide (43.78%) radicals were exhibited by the raw samples. Further, 83.11% of α-amylase and 62.79% of α-glucosidase enzyme inhibition characteristics under in vitro starch digestion bioassay were also recorded. Sprouting + oil-frying caused an apparent increase on the total free phenolic content and a significant improvement in the antioxidant and free radical scavenging capacity of methanolic extract of C. hirsuta seeds, while soaking + cooking as well as open-pan roasting treatments showed diminishing effects. The analysis of the phenolic profile revealed the presence of gallic acid, p-coumaric acid and (+)-catechin in the methanolic extract of these seeds.     

Resistance of the rice variety Utri Rajapan to ragged stunt and tungro viruses

Utri Rajapan, a rice variety tolerant to the brown planthopper, Nilaparvata lugens, was resistant to rice ragged stunt virus transmitted by N. lugens and to rice tungro virus transmitted by the green leafhopper, Nephottetix virescens. Although some Utri Rajapan plants became infected with tungro virus, symptoms were mild and disappeared as the plant matured. Of the two tungro-associated viruses, only rice tungro bacilliform virus was present in Utri Rajapan. The infected plants thus did not serve as a source of inoculum for transmission to healthy plants, as rice tungro spherical virus must also be present for transmission to occur.     

Multilocus genes based characterization of phytoplasma strains associated with Mexican and French marigold species in India

European Journal of Plant Pathology - During the winters of 2018 to 2020, witches’ broom, phyllody, flat stem, little leaf, yellowing and stunting symptoms were recorded in&nbsp;Mexican...